This discussion reminded me of my best Diff Eq prof. He would start each lecture by putting a small clock on his podium, and starting at the precise time listed for the start of the lecture. Then he would leap into action, chalk dust flying around him as he explained the subject of the day. He would often go through more than six full-size chalkboards, having a student erase a few chalkboards behind him so he could return to use the first chalkboard when he ran out of room on the sixth one. Then at the precise time scheduled for the end of the lecture, he would take the clock off the podium and leave the room.

You could often see him walking around campus, covered in a fine white dust, looking like a ghost.

It's been 30 years, and I couldn't remember his name, but man do I remember his lectures.

Update: after typing this, I searched for him, and unfortunately found him almost immediately. He just passed away, and there was a memorial to him on the front page of his math department: https://www.math.fsu.edu/DepartmentNews/Articles/Fac_Nolder....

I note this line from the memorial: His students marveled at his ability to draw a perfect circle on the blackboard with a single stroke.

Here's to you, Dr. Nolder!

As a teacher that uses chalk and white boards I can heartily tell you that chalk sucks. It's messy on your hands and cloths, it breaks and is difficult to erase from the board. White board markers are so much nicer. The criticisms of markers seem to be, from the article:

You can't tell when they will run out. This is not true, they fade out not stop suddenly. Also, it is always possible to carry a spare marker or two.

Hand writing is worse with markers. Then look at what you've written and make it better.

White boards deteriorate faster. I currently use white boards that are a sheet of reinforced glass pained white on the reverse face. They've been installed for 10 years and look the same as they the day there were installed.

Permanent markers destroy a whiteboard. The glass boards make it a little bit of work but it instant destruction.

Chalk is less damaging to the environment than marker pens. This is true but can be mitigated with re-fallible pens.

Special "chemicals" are needed to clean a white board. The chemical that I use is water in order to make the cleaning rag damp. The same as I use for chalk.

It's like writing on paper vs writing on a digital tablet. The difference in tactile feedback leads to better handwriting, at least for me.

I'm curious about the phenomenon they mentioned of "circles being smaller with markers". I definitely noticed that when teaching my overall font size decreased on markers vs. chalk, even when using the skinny chalks. But the effective tip size even with small chalk is larger than that of whiteboard markers. So I wonder if we had big ass whiteboards with big ass tips on the markers if the writing style would be more similar. Or if it's more a function of the resistance you get with chalk+chalkboard. Could we make a whiteboard+marker that had more resistance? Like some hall effect or something. Sounds too complex relative to just using chalkboards.

That being said, a downside I didn't see mentioned was chalk dust. I have asthma but still prefer chalk, but I did not appreciate having to pound the dust out of the erasers when I was in grade school. I wonder if they could make the chalk magnetic and have magnetic trap at the bottom or something. But again too complicated.

Any

    I did not appreciate having to pound the dust out of the erasers when I was in grade school. 
    I wonder if they could make the chalk magnetic and have magnetic trap at the bottom or 
    something. But again too complicated.

Strange question - has the "submitted at" times been edited on this post and all the comments here? I swear I read everything on this submission, including the comments, several days ago, but nothing here is longer than a few hours.

Actually, google search agrees with me - if you search for the title here + hackernews, it says that it saw this post and several of the comments 6 days ago (apologies that I can't link to the cache as this is no longer a feature of Google).

Why are all the post and comment times here saying less than a few hours ago?

          This post number is: https://news.ycombinator.com/item?id=45557970
  A post from 7 hours past is: https://news.ycombinator.com/item?id=45630962

I did all my undergrad in ink, and I loved it. Christmas time allowed me to use red and green and brown markers on my tests. The ball point pens had less friction, and I could write faster. Sometimes, an incorrect answer would still get points as I did not "erase" what I had previously written.

> Conrad also pointed out that if one accidentally applies permanent markers on a whiteboard, then the board would be “instantly dead,” a nightmare not applicable to chalkboards.

Not so.

Like dissolves like. You take a dry-erase marker and over-write the permanent, and then wipe both off.

The weirdest thing about chalkboards is the placebo effect they give to doing math.

I can be a blithering idiot talking math to someone without props but in front of a chalkboard I can be the second coming of Galois.

No, whiteboards don’t give the same buff.

I started to use water soluble crayons (stabilo woody) for my whiteboards and they are great.

The only small drawback is that you cannot easily correct by erasing with your finger (possible but you need to insist)